Exoelectrogenic biofilm as a template for sustainable formation of a catalytic mesoporous structure

Abstract

ABSTRACT Mesoporous structures can increase catalytic activity by maximizing the ratio of surface area to volume, but current synthesis techniques utilize expensive polymers and toxic chemicals. A Geobacter sulfurreducens biofilm was used as a sustainable template to form mesoporous Pd structures while eliminating the need for synthetic chemicals. The bulk of the biofilm material was removed by thermal treatments after nanoparticle formation, producing a catalytic Pd mesoporous (pore size 9.7 ± 0.1 nm) structure attached to the graphite electrode with a 1.5–2 µm thick backbone composed of nanoparticles (∼200 nm). A control electrode electrochemically plated with Pd in the absence of a biofilm exhibited a variable planar Pd base (∼0.5–3 µm thick) with sporadic Pd extrusions (∼2 µm across, 1–5 µm tall) from the surface. The biotemplated mesoporous structure produced 15–20% higher stable current densities during H 2 oxidation tests than the electrochemically plated control electrode, even though 30% less Pd was present in the biotemplated catalyst. These results indicate that electroactive biofilms can be used as a sustainable base material to produce nanoporous structures without the need for synthetic polymers. Biotechnol. Bioeng. 2014;111: 2349–2354. © 2014 Wiley Periodicals, Inc.

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Identifiers

DOI

10.1002/bit.25267

Journal

Biotechnology and Bioengineering

Year

2014